Right now I don't have to worry much about bears as they're hibernating. I rarely see lions but I'm sure they see me. We don't have wolves but they generally won't come in to where you're camped unless you have food sitting around from what I've heard. I camp in bear country and generally sleep out in the open on the ground with no problem. I do keep a clean camp and pay attention to what the bear activity in the area is, and how desperate they are for food, and check the area for bear sign. If you're really bothered about it, cook supper in one place then move away from there to sleep. It's probably just a fable, but I always create a 'whizz fence' around my camp site. Not a good idea to use a lot of aftershave or sweet smelling bath soap before you go out camping. I always have a gun, but that's mainly just to make a loud noise and scare them off rather than try to kill one. The alarm button on my truck works for that too. In this part of the country, you're more apt to be struck by lightning or hit by a falling dead pine tree than attacked by a bear or lion. And luckily, we have no grizzlies here.
